Interior spaces, for example, rooms in residential or commercial buildings, are often illuminated by artificial light from one or more lighting loads, such as incandescent or fluorescent lamps, and/or by natural light, such as sunlight shining through one or more windows. The total light intensity in a space may be measured, for instance using one or more daylight sensors, such as photosensors, which may allow for automated adjustment of the light intensity in the space. For example, a load control device may decrease the light intensity of one or more lighting loads as the total light intensity in the space increases, and/or may increase the light intensity of one or more lighting load as the total light intensity in the space decreases. Daylight sensors are typically mounted to a ceiling within a space at a prescribed distance from one or more windows.
It is often desirable to control the light intensity at the location of a user (e.g., on a task surface) to a desired light intensity. However, because daylight sensors are typically mounted on the ceiling, an associated load control device typically applies a gain factor to the light intensity measured by the daylight sensor before attempting to control the light intensity at the location of the user to the desired light intensity.
Typically, a daylight sensor and an associated load control device must be calibrated before operation, in order to establish an appropriate gain factor to ensure proper operation of the system. Such calibration may be undesirably complicated and burdensome to the average user of a load control system. Additionally, if such calibration is not performed correctly, the system may not operate properly, which may result in a user's inability to accurately control the light intensity at the user's location to a desired light intensity. Examples of calibration methods for daylight sensors are described in greater detail in commonly-assigned U.S. Pat. No. 8,410,706, issued Apr. 2, 2013, entitled “Method Of Calibrating A Daylight Sensor,” the entire disclosure of which is incorporated herein by reference.